Efficacy and safety of antazoline in the rapid cardioversion of paroxysmal atrial fibrillation (the AnPAF Study)

AIMS: The aim of the study was to assess the clinical efficacy of antazoline, a first-generation anti-histaminic agent, in the rapid conversion of paroxysmal non-valvular atrial fibrillation (AF) to sinus rhythm in patients without heart failure. METHODS AND RESULTS: This study was a single center, randomized, double blind, placebo-controlled, superiority clinical trial. We enrolled patients with an AF episode lasting less than 43 h, in stable cardiopulmonary condition. Subjects who fulfilled the selection criteria were randomly assigned to receive intravenously either a placebo or up to 250 mg of antazoline. The primary end point was the conversion of AF to sinus rhythm confirmed in electrocardiogram (ECG). We enrolled 74 patients: 36 (48.6%) in the antazoline group and 38 (51.4%) in the control group. The mean age was 68 ± 12 years (range 31-90 years), 39 (53.3%) patients were male. The successful conversion of AF to sinus rhythm during the observation period was achieved in 26 (72.2%) patients treated with antazoline and 4 (10.5%) in the control group: RR 6.86 (95% CI: 2.66-17.72, P < 0.0001). Median time to conversion was 16.0 min in antazoline and 72.5 min in the control group (P = 0.0246). There were no cases of atrial tachycardia/flutter in the antazoline group. CONCLUSION: Intravenous antazoline was effective and safe in the rapid conversion of non-valvular paroxysmal atrial fibrillation to sinus rhythm in patients without heart failure. Clinical Trial Registration number: NCT01527279.